– treated by supporting the patient (ventilation, hydration) until the toxic or metabolic insult has passed

Distinguishing between structural or metabolic/toxic causes of coma

Toxic/metabolic Coma

Structural Lesions Causing Coma

Diffuse, multifocal deficits

Signs point to a single locus (focal findings)

Signs can fluctuate

May deteriorate in a rostral

Þ caudal progression

Oculo-vestibular responses may be lost

Eye movements are comprimised with brainstem injury

Pupil response to light is usually preserved

Pupil responses can be impaired with brainstem injury

Treat with support and correction of metabolic disorder

May require neurosurgical decompression

Initial management of the comatose patient

Assure oxygenation

Maintain BP and CO

Give Glucose and Thiamine

Restore acid-base and electrolyte balance

Maintain normal body temp

Control seizures

Treat infections

Consider antidotes or dialysis of toxins

Clinical Features

Rostral-Caudal progression

– suggests a unilateral lesion in the cerebrum that leads to uncal herniation which puts pressure on one side of the brainstem. (mass effect because of limited space in the skull and the tentorium bordering the midbrain)

Signs include asymmetric pupils, one eye won’t adduct. As pressure gets worse responses get more asymmetrical